Method and apparatus for manufacturing pottery ware



Feb. 27, 1940. 2,191,857

. unfraon AND APPARATUS FUR MANUFACTURING POTTERY WARE -W. J. MILLER Film-mi2, 193s 2 sheets-sheet 1 INVENTOR. MUA/v /LLf/EL 'TTORNE? Feb. 27,4 19,40. w. J. MILLER IETHOD AND APIARATUS FOR MANUFACTURING POTTERY WAIEIv Filodlay 2, 1935 2 Sheets-Sheet 2 NVENTOR. MUA/mj/V/L EE- Patented Feb. 27,

PATENT OFFICE METHOD AND APPARATUS FOR MANU- FACTURING POTTERY WARE William J. Miller, Swissvale, Pa.

Application May 2, 1935, Serial No. 19,478

25 Claims.

This invention relates to methods and apparatus for manufacturing pottery ware particularly plates, cups and saucers, etc.; known as jlggered dinnerware and heretofore fabricated by manual jiggering processes from plastic clay. It has to do with automatic ware production from clay mass to dried ware with coincidental shaping and dewatering of the clay by pressure, prior to final drying; the procedural apparatus 1 including a ware fabricating mechanism, dryer,

and dryer conveyor preferably operating in timed relation for the progressive stepwise manufacture of ware of this class.

Heretofore, owing to the differences in drying 15 shrinkage of clay, due to variations in moisture content or character, and the extensive shrinko in .the initial formation of the blank to relieve the forming surfaces of excess pressures and/or breaking strains; to eliminate batting out, profiling (except for finishing), sponging, the use of absorbent molds and all of the equipment required therefor; Vto expedite straight line yautomatic production and to reduce clay wastage. percentage of ware loss and substantially eliminate manual intervention.

The procedure embraces the steps of delivm ering successive plastic clay charges of predetermined bulk, shape and minimum practical moisture content to the forming surfaces of a pair of cooperable permeable dies, forming the charge first into a rimmed disc with predetermined thin l regular center section and then progressively spreading and flattening the rim to coincide with the -center section to form a soft, unstable, rough blank having predetermined shape and size closely approaching final ware form but of w excess thickness; repelling the blank fromone of the dies by forcing air under pressure through the permeable walls thereof, advancing the blank t a second permeable die and repressing to eliminate defects from the exposed surface whilst l. maintainingv or reforming the established shape and size; repelling the reformed blank from the die and stepwise advancing it to and'through a series of co-operating permeable dewatering dies by establishing a temporary adhering relationship between the clay and a transfer head having a clay receiving surface of predetermined shape retaining contour; subjecting the blank to a sequence of squeezes of predetermined dewatering intensity each squeeze extending over the major portion of a transfer and squeeze cycle, releasing the clay from the dies by forcing a dry preferably heated gaseous fluid at superatmospheric pressure through the die centers at a high pressure and adjacent die peripheries at a reduced pressure; establishing a high velocity flow .to purge water from the capillary passages of the die, wipe the ware and die forming surfaces of free water and thermally dry the passage walls and die surfaces of residual film water; repeating the dewatering cycles as aforesaid until the blank has been gradually and progressively dewatered and compacted beyond the stage of major shrinkage down to substantially its dry bulk, density, stability and thin regular ware section, without substantial variation in the established size and shape, and Without the production of drying cracks or shrinkage strains; transferring the blank to embellshing dies or a' profile to finally enhance and define the surface thereof, depositing the ware in successive order and in predetermined spaced relation on a dryer conveyor; advancing the conveyor in synchronism with the preceding operations and transporting the ware through a drying atmosphere to remove the remaining Water preparatory to firing.

In the drawings:

Fig. 1 is a sectional elevation of the preferred form of apparatus.

Fig. 2 is a detail in section of the clay feeding and blank forming apparatus.

Fig. 3 is a fragmentary end elevation of Fig. l disclosing various drive mechanisms.

Figs. 4, 5, 6 and 7 are details in section of a pair of dies representing the various stages in the transition of a clay charge into a blank.

Fig. 8 is a detail partly in section of a cam operated control valve.

Fig. 8a is a fragmentary section of a pair of dies with co-perating brim sealing members and an approach adjustment.

Fig. 9 is an elev tion disclosing a method and a charge forming and feeding apparatus A, a turret B having a plurality of demountable snap-- ing and/or dewatering dies I mounted thereon, a ware transfer C, having transfer heads 44, lower dewatering die assembly 2b and upper and lower dewatering die assemblies Ia and 2c respectively, finishing die assemblies 2d and Ib together with driving and synchronizing mechanism operated by motor D, these several apparatuses forming one line of a contemplated multiple of parallel lines of production including a drier E and a Ware conveying apparatus H common to one or more lines of production. 'I'he fabricating machine operates in repeated cycles and completes one piece of ware in a line at the termination of each machine cycle, the other pieces of ware yet in the machine being advanced one step toward completion.

A conditioned and preferably heated clay billet I, Fig. 2, is placed manually on belt 3 and advanced by spring actuated adjustable stroke rod 4 into a compacting chamber 5 formed by pivoted jaws 8, thereafter closed as linkage |01 is shifted to left, through spring Ina, Fig. 2, cam 'I on shaft 8 driven from main shaft 8a, Fig. 1, by chain 9. The jaws segregate and compact a measured charge of clay J, and, incident to jaw closing, the belt actuated pawl ll is reset on ratchet I2 by cam 1a through linkage I8 for the next succeeding advance of billet I.

The charge J is then progressed through bushing I3 in open center 'male die holder 2e by pourous faced plunger I4 adjustably secured to cross head I5, and onto the contoured face of a rising female die I, on elevatable turret B, Figs. 1 and 2elevated by cam I 5, Fig. 1, through toggle I'I, cross head I8, pressing unit I8 and cooperating dewatering dies I and 2b; plunger I4 recesses the center portion of the charge J, Fig. 5, and presses it against the die to establish a predetermined relatively thin center section K, the remaining material forming a thick section ring L around the plunger, Fig. 5. Upon continued elevationof die I, the ring L. is uniformly distributed in a radial direction to relatively thin regular section andthe clay compacted against, defined and supported by the chamber' wall, Fig. 6, thus forming a soft, highly plastic blank M.

The center thickness of the blank is maintained by elevating the plunger in unison with die I, through cross head I8, Fig. 3, and rods 22 adjustably secured in cross head I5. As cross head I8 rises, cross head I5 is moved downwardly by one of the interconnected toggles I1 through links 23 connected to an extension 20 below a fixed pivot 2I, Fig. 3' and to cross head I5 through a resilient terminal assembly 24 and as rods 22 engage cross head I8, the plunger and cross head I5 are elevated in unison therewith due to the lost motion in terminal assemblies 24.

Radial spreading and/or expansion of the charge J is thus divided into two pressure stages, each of a lower value than the high pressure normally required to completely spread a charge in one continuous operation from mold center to brim. This relieves the relatively fragile dies of excess pressures and breaking strains. The charge is normally shaped between the dies on all surfaces into a rough blank M of predetermined size and shape closely approximating that of the nished Ware except for plunger marks, excess thickness and plasticity and at a moderate pressure of slight dewatering intensity.

The ware and/or blank brim is defined vand compacted by a ring of resilient material 2t, such v as rubber, preferably mounted on or in each die of a pair, in grooves 2gat the brim of the matrices, Fig. 8a. Its'resiliency permits variable approach of a pair of dies' for determining blank and/or ware thickness and on separation of the dies, progressively parts from the blank and/or ware brim to avoid deformation thereof. The closest approach of the dies at any station may also be limited by a pair of opposed adjustment screws 27', Figs. 7 and 8a.

Coincident with an initial separation of dies I and 2, the blank is repelled from the upper die by forcing a dry. gaseous and preferably heated uid under control of valve F, Fig. 8, through the permeable matrix. The plunger is dropped in unison with the lower die approximately 54; of an inch thereby mechanically forcing the yblank oil! the upper die surface before it is repelled n from the arrested plunger. The turret then continues in its descent and comes to rest at the bottom of guides 28, Fig. 1, on trunnions 28 and is then rotated counter-clockwise a quarter turn by cam 30 on shaft 8 through ,spring 38a lever 3l, lost motion connection 8Ia, pawl 32 and ratchet wheel 32a. The lost motion connection permits a die 2a to be withdrawn by lever 3l prior to rotation of a turret. A spring pressed detent 32h locates and holds the turret stationary after each turn.

Upon the succeeding elevation of the turret, the closed center die 2a mounted in a rassaged base 2e on passaged stem 34 pivotally connected to lever al and having guide bars sa is advanced by lever 3| into co-operation with the blank to press and remove the plunger marks, complete the expansion of the blank (if such has not been entirely completed theretofore), and redefine its shape and contour, the pressure applied being preferably of slight dewatering intensity. The degree of pressure is adjustable through spring 34a encompassing rod 34 and nut l5.

After die 2a is withdrawn and the blank repelled, the turret is then lowered and rotated counter-clockwise one division to locate the blank in inverted position over die 2b on elevatable left end pressing unit I9, simultaneously registering conduit 25 leading to die chamber.

21a with a closed high pressure line 25a under control of valve F. When die Zb'rises, a pressure load of dewatering value is imposed on the blank by the weight of the turret to commence the dewatering and compacting thereof as'the turret is elevated, the maximum load on the blank occurring incident to the closing of dies I and 2 and the pressing of a charge J. Any excess pressures are dissipated by spring 28, adjustable for tension by threaded stem 28a with detent 2Gb for locking although the possibility of the occurrence of such is minimized by the stepwise application of pressure in the spreading of the charge. The blank is preferably squeezed at a moderate pressure to remove shrinkage water but at an increase over that occurring during the previous stages, but not to a major extent, the clay being compacted to a degree of stabilization enabling subsequent pick-up, transfer and redeposit by a form retaining head without harmful shape deformation.

'I'he shrinkage water expelled at this or any prior forming station or subsequent dewatering station is free to move and enter the capillary passages of the permeable dies at or below atmospheric pressure and is subsequently purged 75 therefrom incident to repelling of the blank. In

the discharge of expelled water it is preferred to slightly separate the dies, Fig. 7, and repell the clay from one of the forming surfaces. for instance die I, the iiuid being forced through the center at a high pressure to avoid center stagnation and through the concentric peripheral zone at a lower pressure. I'his establishes a radial flow inthe narrow gap between blank and matrix toward the brim and besides repelling the blank, purges the capillary passages of the die of any held water and wipes the ware and die forming surfac ofl freewater whilst thermally drying the passage walls and die surface of residual iilm water, subsequently subjected to fan G.

Accordingly, when the turret is lowered, the blank is repelled from die I and deposited on die 2b, the die I purged and then dies I and 2b are fully separated. A transfer frame C is then shifted to the left by cam 40 on shaft 4I through spring 42 and adjustable jointed linkage 43 to center a transfer head 44 over the blank. The frame is then lowered by cam 46 on shaft 46a through spring l4I and jointed linkage 48 and the semi-stabilized blank secured to the contoured surface of the head by suction. The transfer is then elevated coincidently with purging of die 2b, then completely elevated and shifted to right, lowered and the blank deposited on die 2c as suction is discontinued. The transfer is then returned to intermediate position, Fig. 1, and the blank elevated into engagement with die Ia and finally dewatered down to substantially its dry bulk, density and I thickness, the degree of pressure being substantially higher due to the increased density of the blank and being held preferably for a period representing the major portion of a transfer and squeeze cycle.

After final dewatering, the shaped blank is transferred to die 2d and lpressed against a finishing die Ib demountably attached to lintel 49 and having a contoured and polished surface for embellishing the exposed surface of the blank. A prole may be substituted if desired such as that shown in my co-pending application, now matured into Patent No. 2,046,525, together with instrumentalities for spraying fluid for moistening the blank surface prior to 'or during profiling and driving the chuck spindle intermittently through a motorcontrolled by adjustable cam operated switch 36, Fig. 8. It is understood that the dies 2b and 2d are elevated in unison by virtue of a cross link 31 connected across the knees of toggles I1.

The completed ware is transferred after embellishment to and deposited on a form retaining support 50 of one of a plurality of spaced trays 5I pivotally suspended from the chains 52 of a short length drier conveyor operating in drier E and in synchronism with the transfer C and fabricating mechanisms from driven shaft46a (driven in unison with shafts 4I and 8a by chains 38-and 39, Fig. 1,) chain 53 sprocket 54, motion plate 54a 'and Geneva 55 on shaft 58 carrying drive chain sprockets 51.

'I'he low percentage of residual moisture in the ware precludes shrinkage strains and distortion during drying and insures uniform predetermined diameter and ware shape. Since the critical shrinkage period is avoided, the drying time required is considerably reduced by the immediate application of high temperature, low humidity air. After traversing the drier, the ware is removed preferably at R and may be then further processed or transferred directly to the kiln.

The dies disclosed herein. the clay contacting face of the plunger and the clay engaging faces of the transfer heads are preferably made of permeable material. The dies are mounted in bases 2e and sealed therewith around the brims and forming a hollow central chamber 21a and a concentric peripheralchamber 2lb separated by an upstanding ring of material 15. Both the plunger and the transfer heads are chambered behind the permeable faces and such chambers as well as chambers 21a and 2lb are in communication with a source of sub and/or super atmospheric pressure controlled by one or more valves, Fig. 8, to control clay adhesion to and/or repulsion from the surfaces in question. I'he valve is substantially the same as that shown and described in my Patent 2,046,525', having a phase changing control 58 and cams 59 and intermittently reciprocating a passage slide valve 50 between suction inlet 6I, super atmospheric pressure inlet 62 and an outlet 63. The chambers 21a and 2lb in the dewatering die assemblies are interconnected by passage 64 having an adjustable reducing valve 84a therein.

I have shown in Fig. 9 that the system may be practiced on travelling absorbent molds 65, a conveyor 61 advancing the molds cyclically on one or more lines to and through a dryer and back to temporary halted position first under the turret for the application of a formedblankthereto, then under the succeeding dewatering and finishing dies, the molds being elevated at each station by chucks 68 through the open bottoms of trays 69. The resiliency of rectangular section brim seating ring 69 and circular section center ring I0 on chucks 68 insures mold stabilization, proper seating thereof and equal distribution of pressures thereon incident to the pressing operations, the mold having chip collecting grooves 10a to prevent interference thereof with mold seating. This subject matter is more fully disclosed and claimed in a co-pending application, now matured into Patent 2,046,525.

It is entirely within the spirit and scope of this invention to operate the fabricating device and dryer separately with manual transfer of the ware therebetween. Any number of these fabricating instrumentalities may also be arranged in side by side relation for the operation of a plurality of parallel lines of production either with or without a synchronized conveyor.

.I claim:

l. In apparatus for the manufacture of dinnerware the combination which comprises a plurality of pairs of cooperable means for dewatering clay bodies each pair forming therebetween a clay receiving and dinnerware shaping cavity, means for transferring clay between one pair of dewatering means and another, a dryer having a conveyor therein and means for operating said conveyor in timed relation with said transfer means.

2. In apparatus for the manufacture of potteryware, the combination which comprises a continuous chain conveyor and a fabricating apparatus, means for operating said fabricating apparatus and said conveyor in timed relation, a transfer operating between said fabricating apparatus and conveyor for transporting fabricated articles from one apparatus to the other, said fabricating apparatus including a plurality of means for pressing clay bodies, means for varying the degree of pressure applied whereby said clay charges, means co-operable with said dies for shaping said clay, a plurality of pairs'of dies arranged in sequence adjacent said turret, means for transferring shaped clay to and between said last named pairs of dies, a conveyor and means for operating said conveyor and said transfer means in timed relation.

5. Apparatus for the manufacture of pottery ware which comprises, in combination, an automatic clay feeding apparatus, a turret having a plurality of dies thereon, means for rotating said turret to successively present said dies to said feeding means, a plurality of independently movable dies arranged adjacent said turret and co operable with the dies thereof, means for applying sub and/or super atmospheric pressure to said dies, and a plurality of pressing means arranged in sequence and adjacent said turret and transfer mechanism operating between said turret and said pressing means.

6. In apparatus for the manufacture of pottery ware the combination which comprises, an automatic pottery ware fabricating machine, a dryer and a conveyor operating in said dryer, means operating in timed relation with said conveyor for removing ware from said machine and depositing the same on said conveyor, said means including a plurality of suction cups adapted to I transport ware in different stages of fabrication from one position on the machine to another incident to transferring ware to the conveyor.

7. Apparatus for the manufacture of potteryware which comprises, in combination, an automatic clay feeding apparatus, a turret `having a plurality of female dies associated therewith, a male die adjacent said turret, means for rotating said turret to present said female ldies rst to said automatic clay feeding apparatus and then to said die; means for moving said male die into and out of co-operation with said female dies; means for releasing said male die from said clay; a crosshead, a chuck carried thereby, a die supported by said chuck and adapted to co-operate with the female dies of said turret and to elevate said turret and a transfer for removing clay from said last named die.

8. Apparatus for the manufacture of pottery- Ware which comprises, in combination, a rotatable turret having a plurality of dies associated therewith, means for feeding clay into said dies and means for removing clay after shaping from said turret, a plurality of co-operable die bodies, means for transferring shaped clay thereto, means for elevating one of said dies to squeeze clay between it and its companion die and means for controlling the degree of pressure applied to said clay. l

9. Apparatus for the manufacture of potteryware which comprises, in combination, a rotatable turret having a plurality of dies mounted therein, means for feeding clay into said dies,

susi-,asv

means for forming said clay into undewatered blanks.' means for removing said blanks from said turret and ineans for squeezing said blanks to expel water therefrom, said' means comprising a pair of permeable matrices, means for moving one of said matrices relative to the other and meansfor varying the degree of pressure applied to said blanks.

vl0. Apparatus for the manufacture of potteryware which comprises, in combination, a rotatable turret having a plurality of dies mounted therein, means for feeding clay into said dies, means for forming said clay into undewatered blanks, means 'for removing said blanks from said turret and means for squeezing said blanks to expel water therefrom, said means comprising a pair of permeable matrices, means for moving one of said matrices relative to the other and means for varying the closest approach of said matrices.

1 1. Apparatus for the manufacture of potteryware which comprises, in combination, a rotatable turret having a plurality of dies mounted therein, means for feeding clay into said dies, means for forming said clay into undewatered blanks. means for removing said blanks from said turret and a plurality of means for squeezing said blanks to progressively remove 4water therefrom, said means comprising pairs of permeable matrices and means for limiting the closest approach of the matrices of apair and adjustable means for regulating the degree of pressure applied to said blanks.

12. An apparatus for the manufacture of potteryware which comprises, in combination, a clay shaping mechanism, means for dewatering clay,

a clay transfer and a dryer, mechanism for operating said clay shaper, means for operating said dewatering mechanism and means for operating said transfer in timed relation withI said clay shaping and said dewatering means.

13. Apparatus for the manufacture of potteryware such as plates, cups, saucers and the like from plastic clay comprising, in combination, means for shaping clay bodies out of plastic clay by pressing comprising permeable die surfaces, means for dewatering shaped clay by pressing comprising permeable die surfaces and means for varying the pressure applied to the clay incident to shaping 'and dewatering.

14. Apparatus for the manufacture of potteryware comprising, in combination, means for shaping clay bodies, means for dewatering previously shaped clay bodies comprising a plurality of dies having permeable clay engaging faces and means for applying sub and super atmospheric pressure through the faces of said dies to draw the liquid constituents of the clay squeezed from said clay incident to dewatering into the dies and to purge the dies thereof through their faces, respectively.

l5. Apparatus for the mass production manufacture of potteryware comprising, in combination, a plurality of pairs of permeable pressing dies arranged in sequence and forming a production line, means for feeding the line with individual clay charges, means for transporting the clay in various stages of fabrication along the line, means for opening and closing the dies to rst shape the clay charge and then dewater the same as the blanks progress along the production line and a dryer for receiving the clay bodies subsequent to dewatering.

16. Method of manufacturing potteryware such as plates, cups, saucers and the like from plastic clay which consists in first pressing a clay mass 78 at less than dewaring pressure to shape the same and then immediately repressngthe preformed clay mass at pressures of dewatering intensity whilst maintaining the pre-established shape to remove a material portion ot the water therefrom.

17. A process for the manufacture of ceramic ware such as plates, cups, saucers and the like which comprises, preparing a plastic mass comprising clay and water, forming the mass to the desired shape and materially reducing the water content by the application of mechanical pressure to the mass while the mass is in contact with a permeable support into which the water passes, releasing the pressure' and then expelling the water from the permeable support.

18. A process for the manufacture of ceramic ware such as plates, cups, saucers and the like which comprises, forming a mass of plastic clay having a water content which will promote plastic deformation between permeable supports which permit the passage of water thereinto, applying mechanical pressure to the mass to expel water therefrom into the permeable supports while at the same time shaping the mass and compacting and densifying it, releasing the pressure land separating the clay from the permeable supports and purging the supports of held water.

19. A method of making potteryware which comprises. squeezing a clay mass containing water between permeable shaping members, expelling the water into the shaping members whilst consolidating the clay, releasing the pressure'and separating the shaping members and blowing the water removed from the clay back onto the surface oi the clay.

20. Apparatus for the manufacture oi potteryware-such as plates, cups, saucers and-the like from plastic clay comprising, in combination,

means for shaping clay bodies into ilnal ware form by the application of a sequence of pressures thereto, and means for repressing the formed bodies to pvely remove shrinkage water therefrom; compact the clay and reduce the body to substantially its dry bulk and density and means tor actuating said shaping means andl being substantially of a leather hard character and a dryer for the reception of the shaped, dewatered ware.

22. In combination with a mold, apparatus for forming mold bonded clay bodies comprising a pressing instrumentality vadapted to co-operate with the central zone of the molding surface of a mold to press upon and reduce that portion of a charge of clay over-lying the central zone to a predetermined thickness, means operable prior to the Withdrawal of the pressing instrumentality to distribute the remainder of the charge of clay over the exposed portion of the molding -surface and reduce the same to a predetermined thickness thereby dividing the formative process into'successive stages and reducing the pressure required to move the vclay over the surface of the mold and means for releasing the pressing instrumentality and distributing means from the surface of the clay.

23. A method of forming a mold bonded clay body which comprises, depositing a charge of clay on the center of distribution of the molding surface of a mold and then pressing out the central portion of the body to the thickness desired in this portion of the blank thereby leaving a ring tion and then applying pressure to said ring of unpressed clay whilst holding the central portion of the blank atthe pre-established thickness to thereby cause the previously impressed clay to be distributed over the exposed portion of the mold in a direction toward the brim thereof thereby completing the formation of the mold bonded clay body.

Y 24. Apparatusffonthe,manufacture cf potteryware comprisinggicombination, a press for shaping clay bodies including permeable means for squeezing clay bodies therebetween to remove water from the said clay, means for applying air under pressure through the permeable means operable upon separation of said permeable means `to purge said permeable means of held water and eject the same in the direction of the clay body.

25. In apparatus for manufacturing potteryware such as plates, cups, saucers and the like from plastic clay, means for applying mechanical pressure to uniormed clay bodies to distribute the material over a molding surface andshape the same, said means being adapted to allow free movement of the liquid constituents of the clay body by being constructed of a permeable material together with means for applying mechanical pressure to the clay in said shaped clay bodies at a value which will move the liquid constituents out of the body, said last named means being adapted to allow free movement of the liquid constituents by being constructed of a permeable material.

WILLIAM J. LDILER.

of unpressed clay surrounding the central por- 

